Writable optical digital video disks (DVDs) store information on the DVDs in two different manners. Data information is recorded onto tracks as a DVD spins.
The tracks spiral around the center of the DVD in a sinusoid pattern called the wobble pattern. A second type of information called wobble information is encoded in the wobble pattern.
Information related to addresses used to store information on the data tracks is stored in the wobble pattern. Timing information needed to generate a write clock for writing the optical disk is also stored in the wobble pattern. The data information and wobble information are typically read and processed independent from each other. For example, different hardware, sensors, and demodulation techniques are used to read the data information and the wobble information. Additionally, typically the data information and the wobble information are read at different bit rates. The data information and wobble information are usually decoded using different modulation techniques.